Why do they not use copper ?

[micah]

Reading the reviews on the new 6800 I started thinking. Why do they use Aluminum and not copper on graphic cards heat sinks ?
They seem to keep getting bigger and bigger yet they stay with Aluminum instead of switching to copper like CPU heat sinks use. I am sure it could figure out a way to support the extra weight as it is not all that much. I would say they could get away with a smaller copper one than they can with a aluminum ones. Might even being bale to stay in just the 1 bay and not take up the extra PCI slots like so many are not days.

And even that (Using a PCI slot) brings up a point in how they could help support the weight. They could build it so that both the APG and PCI was supporting it. I have seen things that used the PCI slot as support that was just plastic or something so it could not short anything out or anything. But that could help support a lot of weight between the 2 slots.

Well anyway does anyone know why they are not switching to copper ? Even some are copper coating them like MSI. I have the MSI 5900XT and it looks like it is copper but I read where it is just copper coated aluminum.

 

[Oppy]

weight, its all about the weight. your questions are valid ones , but remember this is just a pre production model so who knows , what the other companys might come up with.

 

[Merlin45]

2 things,
#1 is that not all boards have a pci slot next to the agp slot, so you can't use it for support.
#2 aluminum is cheaper, lighter, and the differences between the two aren't very big, the design of the cooler has much more effect than the material it is made of.

 

[IceWindus]

1. Weight
2. Cost.

Simple as that.

 

[drewb99]

Gold is a better heat conductor than copper, but we don't see pure gold heatsinks for pretty obvious reasons.

 

[Bad_Boy]

haha

when i become rich and famous, ill have me a 6800U with a gold heatsink bling bling

 

[snowwie]

Originally posted by drewb99
Gold is a better heat conductor than copper, but we don't see pure gold heatsinks for pretty obvious reasons.

dude, you're wrong there, gold isn't a better heat condudctor then copper

in response to the topic, copper isn't a wonder heatsink
it's slightly better than copper, but alu is better when you factor in weight and cost, like others have already said.

 

[HarryPleasure]

Originally posted by drewb99
Gold is a better heat conductor than copper, but we don't see pure gold heatsinks for pretty obvious reasons.

with the pricetag on these cards, they should be gold lol

 

[mcryptic]

actually gold is a worse conductor then copper, but still better then aluminum.

Thermal Properties of Materials
Thermal Conductivity, W/cm-K
Aluminum 2.165
Gold 2.913
Copper 3.937
Silver 4.173
Diamond (room temperature) 6.299

 

[DryFire]

I think he's confused between electrical and thermal conductivity

 

[drewb99]

I was in the ballpark at least

 

[berky]

Originally posted by mcryptic
Diamond (room temperature) 6.299

I want daimond heatsinks!!!!!!!!!!!!!!!!!!!

 

[snowwie]

Originally posted by DryFire
I think he's confused between electrical and thermal conductivity

it's approximately the same deal for electical conductivity, copper is still better than gold

sorry for the nitpicking, but i have nothing better to do

 

[mcryptic]

Originally posted by berky
I want daimond heatsinks!!!!!!!!!!!!!!!!!!!

I wonder why no one has made any thermal paste with diamond instead of silver? I did a little google'ing a while ago and was able to find diamond powder at or smaller to the size that arctic silver uses, and it was cheap too. I guess their won't much of a market for it since there is very little improvement using silver over zinc oxide (cheap white stuff), and i doubt there would be any improvement for using diamond over silver...

 

[gb25]

Originally posted by mcryptic
I wonder why no one has made any thermal paste with diamond instead of silver? I did a little google'ing a while ago and was able to find diamond powder at or smaller to the size that arctic silver uses, and it was cheap too. I guess their won't much of a market for it since there is very little improvement using silver over zinc oxide (cheap white stuff), and i doubt there would be any improvement for using diamond over silver...

I'm pretty sure that Nevin of Arctic Silver has tried to use diamond in a thermal paste before. I think he determined that he didn't work very well, especially considering the high cost.

 

[LightSwitch]

copper=heavy